April lo, 1890] 



NATURE 



533 



Konocte (or Uncle Sam) hot springs and solfataras are 

 abundant in a small area of basalt of comparatively 

 recent origin. The most important of these, known as 

 the Sulphur Bank, was at first worked for sulphur, but, 

 on getting below the surface, cinnabar was found in the 

 decomposed basalt, and for some years it produced large 

 quantities of mercury, up to 11,152 flasks in 1881 ; but 

 latterly the yield has fallen off, being only 1449 flasks in 1886. 

 The Redington Mine, adjoining Knoxville, about 25 

 miles south-east of Clear Lake, was discovered in making 

 a cutting for a road, and has been worked since 1862, and 

 has produced nearly 100,000 flasks of mercury, a quantity 

 which has only been exceeded by the mines of New 

 Almaden and New Idria. In 1886 the yield had fallen 

 to 409 flasks, the immense irregular body of ore at the 

 surface having changed in depth to some narrow veins 

 following fissures in the metamorphic Neocomian strata. 

 These are to a large extent converted into serpentine ; and 

 a black opal, known as quicksilver rock, accompanied the 

 ore, which was remarkable as consisting largely, in the 

 upper workings at least, of amorphous black sulphide of 

 mercury, or meta-cinnabar, a mineral that was there 

 recognized in quantity for the first time. This deposit is 

 considered to be the result of the action of hot springs 

 in connection with an adjacent mass of basalt — springs 

 which are now dormant except in so far that sulphur gases 

 are given off and sulphur crystals are deposited in the old 

 workings, where a comparatively high temperature, ex- 

 ceeding 100° F., prevails. 



The Steamboat Springs in Nevada, near the Comstock 

 lode, have been also studied by the author. These, 

 although presenting no deposits of commercial value, 

 are interesting from the light they cast upon the pheno- 

 mena of the formation of mineral veins, and have there- 

 fore been carefully investigated by several observers, 

 including the late Mr. J. A. Phillips, F'.R.S., and M. 

 Laur, of the Ecole des Mines. The author considers 

 that the main source of the ore in the Comstock lode is 

 the diabase forming the hanging wall, and that the mine- 

 ral contents were extracted from this pre-Tertiary erup- 

 tive mass by intensely heated waters charged with alkaline 

 carbonates and sulphides rising from great depths, and 

 that a similar origin may properly be attributed to all the 

 cinnabar, pyrites, and gold found in the mercury-mines of 

 the Pacific slope, having been brought in as solutions 

 as double sulphides of metal and alkalies. The original 

 source must have been either the fundamental granite of 

 the country, or some ////ra-granitic mass, it being ex- 

 tremely improbable that they were extracted from any 

 volcanic rock at or near the surface. In connection with 

 this subject, the author has made a series of interesting 

 experiments on the relations of the sulphide of mercury 

 to that of sodium, which show that mercuric sulphide 

 is freely soluble in aqueous solutions of sodium sulphide, 

 although the contrary has repeatedly been asserted. 

 Mercuric sulphide may be precipitated from sulpho-salt 

 solutions in many ways, particularly by excess of sul- 

 phuretted hydrogen, by borax and other mineral salts ; 

 by cooling, especially in the presence of ammonia, and 

 by dilution. In the latter case, a certain quantity of 

 metallic mercury separates as well as the sulphide, in- 

 dicating one of the methods by which the native metal 

 has been produced in Nature. 



In addition to the mines specially described, the author 

 has extended his study of the subject to a consideration 

 of the principal mercury-mines other than those of Ame- 

 rica, partly from personal investigation in Spain and 

 Italy, and partly with the help of other observers and 

 published accounts. He expresses a very decided opinion 

 against the supposed substitution origin of the Almaden 

 deposits, considering them to be essentially of a vein-like 

 character, the cinnabar being deposited in fissures or 

 interstitial cavities in sandstone previously existing. This 

 latter conclusion is substantially similar to that arrived 

 at by the late Mr. J. A. Phillips and the present writer, in 

 a microscopic study of the Almaden ores made some 

 years since. The details of the foreign deposits have 

 been very carefully collected, the comparatively new dis- 

 coveries of Avala in Servia, and Bakmuth in Southern 

 European Russia, being included. The latter mine, 

 which, at the time the book was completed, was not at 

 work, has since become of considerable importance. The 

 ore, cinnabar, occurs as an impregnation of a bed of car- 

 boniferous sandstone from 14 to 17 feet thick, with an 

 average yield of 1 54 pounds per ton — about 7 per cent. — 

 and the reduction works have a productive capacity of 

 about 10,000 flasks annually. 



In conclusion, it is scarcely necessary to state that the 

 whole of the details illustrating the subject have been 

 worked out with the care and fulness which have charac- 

 terized the author's former monograph on the Comstock 

 lode. Whether mercury-mining in California may be in 

 a declining state, or destined to a revival of its former 

 prosperity at a future time, there can be no question of 

 the high value of the record of the results hitherto 

 obtained, which is contained in the volume it has been 

 our pleasant task to notice. H. B. 



OUR BOOK SHELF. 



Illustrations of some of the Grasses of the Southern Pun- 

 jab, being Photo-lithographs of some of the Principal 

 Grasses found at Hissar. By William Coldstream, 

 B.A., Bengal Civil Service. With 38 Plates and 8 pages 

 of Introduction. (London: Thacker and Co. Calcutta: 

 Thacker and Spink. 1889.) 

 This work contains a series of thirty-eight photo-htho- 

 graphs of the grasses used for agricultural purposes in the 

 southern portion of the Punjab. The tract of country to 

 which it relates lies to the west of Delhi, between the 

 Jumna on the east and the Sutlej on the west. It con- 

 stituted till recently the civil district of Hissar, which has 

 now been broken up. It has an area of 8500 square 

 miles, and a population of a million and a half Except 

 along the streams and canals the soil is sterile and sandy, 

 and the crops depend upon the periodical rains. The 

 staple cereals are Sorghum vulgarc and Penicillaria 

 spicata. In its centre is situated the great Government 

 cattle-farm of Hissar, where for many years cattle of the 

 finest Indian breeds have been reared by Government, 

 principally for the supply of the ordnance and transport de- 

 partments, but also to some extent for distribution through 

 the country, with the aim of improving the commoner 

 indigenous kinds. The Bir, or grass-lands, of this great 

 farm are of very wide extent, and in the rainy season a 

 large number of grasses, of more or less value as fodder, 

 grow luxuriantly over its vast parks. The farm has alto- 

 gether an area of above sixty square miles, and it is 

 mainly from this that the species figured by Mr. Cold- 

 stream are taken. 



